A034170 Disjoint discriminants (one form per genus) of type 1.

5, 13, 21, 33, 37, 57, 85, 93, 105, 133, 165, 177, 253, 273, 345, 357, 385, 1365

Offset: 1

Author

Jonathan Borwein (jborwein(AT)cecm.sfu.ca), Stephen Choi (choi(AT)cecm.sfu.ca)

Keywords

• nonn
• fini
• full

Comments

A subsequence of A000926, A139826, and A232528. - Andrew Howroyd, Jun 09 2018

References

• L. E. Dickson, Introduction to the theory of numbers, Dover, NY, 1929.
• J. M. Borwein and P. B. Borwein, Pi and the AGM, page 293.

Crossrefs

Cf. A000926, A004766, A034169, A139826, A232528.

Programs

PARI

ok(n)={n<>1 && n%4==1 && issquarefree(n) && !select(t->t<>2, quadclassunit(-4*n).cyc)} \\ Andrew Howroyd, Jun 09 2018

Formula

Intersection of A004766 and A139826. - Andrew Howroyd, Jun 09 2018